The advent of virtualization technologies for computing resources has provided benefits with respect to managing large-scale computing resources for many customers with diverse needs and has allowed various computing resources or computing services to be efficiently and securely shared by multiple customers. For example, virtualization technologies may allow a single physical computing machine to be shared among multiple customers by providing each customer with one or more computing instances hosted by the single physical computing machine using a hypervisor. Each computing instance may be a guest machine acting as a distinct logical computing system that provides a customer with the perception that the customer is the sole operator and administrator of a given virtualized hardware computing resource.
A request to launch a computing instance may entail identifying available computing resources (e.g., a computing slot in a hypervisor) on which the computing instance may be executed. For example, one or more physical computing machines (e.g., server computers) may be queried to determine whether sufficient computing resources exist on a physical computing machine to launch and execute a computing instance. In a case where a physical computing machine is identified as having computing resources available to execute the computing instance, the computing instance may be launched on the physical computing machine, and a customer may be notified that the computing instance has been launched.